PA vs USA

PA and USA both are nouns.

Word	Noun	Adjective	Verb	Adverb
PA	Yes	No	No	No
USA	Yes	No	No	No

PA (noun)	USA (noun)
an electronic amplification system used as a communication system in public areas	the army of the United States of America; the agency that organizes and trains soldiers for land warfare
a Mid-Atlantic state; one of the original 13 colonies, with capital Harrisburg	North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776